On Wed, 2017-05-17 at 11:58 +0100, Mel Gorman wrote: > The race is a non-issue unless for some reason you decide to hot-add the node > when the machine is already heavily loaded and under memory pressure. Do it > near boot time and no CPU-local allocation is going to hit it. In itself, > special casing the core VM is overkill. > > If you decide to use ZONE_MOVABLE and take the remote hit penalty of page > tables, then you can also migrate all the pages away after the onlining > and isolation is complete if it's a serious concern in practice. > > > Unless we have a way to create a node without actually making it > > available for allocations, so we get a chance to establish policies for > > it, then "online" it ? > > > > Conceivably, that could be done although again it's somewhat overkill > as the race only applies if hot-adding CDM under heavy memory pressure > sufficient to overflow to a very remote node. I wouldn't dismiss the problem that readily. It might by ok for our initial customer needs but long run, there's a lot of demand for SR-IOV GPUs and pass-through. It's not far fetched to have GPU being dynamically added/removed from partitions based on usage, which means possibly under significant pressure. That said, this can be solved later if needed. Cheers, Ben. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
